When a large area of concrete is poured, it may be desirable to maintain the same grade or elevation across the entirety of the surface. While this might be simply achieved over a small area, large areas are generally more challenging and generally require some form of grade or elevation markers. One approach to maintaining the grade across a large area is to divide the area into smaller strips or bays, into which concrete will be poured individually and adjacent in conjunction with one another while the concrete is wet. The grade is achieved on the first slab and the grade for each subsequently poured strip is based, in part, on the grade of the first slab. This is generally done by an individual who uses a hand float to level out a small portion of the concrete and uses a sight rod or laser level to ensure that it is level before marking that portion as top of slab. This may sometimes be referred to as wet screeding. The remaining concrete in that particular strip is then screeded based on the marked top of slab portion.
Basically, wet screeding is a process of establishing grade or elevation on the surface area of poured concrete. More specifically, wet screeding is the act of striking off freshly placed concrete with a straight edge to a set or desired elevation by means of using adjacent strips, ribbons, or pads of concrete which have already been screeded or floated to the desired elevation, and while the adjacent concrete is still in a plastic state. As the straight edge is pulled across the top of the concrete, excess concrete is pulled out of the way to make a level surface, and places that are too low have concrete added to them until the grade is uniform. Once a bay or strip of the concrete slab is screeded, the adjacent bay or strip is poured and the grade for the newly poured concrete is based, in part, on the previously completed bay or strip.